Method and apparatus for rivet removal

Abstract

A method and apparatus for the removal of rivets from steelwork employs a high velocity narrow stream of water, containing abrasive particles, to cut through the head of the rivet in a circular path that produces a ring. The remainder of the rivet is then easily extricated from the steelwork. The apparatus includes a cutting head assembly having a nozzle that is driven in a circular path. A mounting device removable anchored to the steelwork supports the cutting head assembly.

1 ) A method for removing from steelwork iron rivets having a circular cylindrical shaft terminating in a first, manufactured head and an opposite second head, said method comprising cutting through at least one head of said rivet in a circular path congruent with the cylindrical surface of said rivet shaft, thereby removing as a ring the portion of the outer extremity of the head that extends outwardly beyond the shaft, then pushing upon the remaining center portion of said head to dislodge the rivet, said cutting being accomplished by a high velocity narrow stream of water containing suspended abrasive particles.  
   
   
       2 ) The method of  claim 1  wherein the cutting action of said stream is caused to continue past said head in tangential contact with said shaft and emerge through said opposite head, thereby producing a second ring.  
   
   
       3 ) Apparatus for removing an iron rivet from engagement with steelwork comprising: 
 a) an ultra-high pressure pump capable of providing water pressurized to at least 35,000 PSI,    b) water filtration means for supplying filtered water to said pump,    c) means for entering particulate abrasive material into said water,    d) a cutting head assembly, including a nozzle, which receives said abrasive-containing pressurized water and directs it as a narrow, high velocity stream capable of cutting through steel,    e) mounting means for supporting said cutting head and achieving accurate positioning thereof with respect to a rivet targeted for removal,    f) drive means associated with said cutting head assembly for causing said nozzle to move in a circular path congruent with the cylindrical surface of the rivet shaft, and    g) collection means disposed in spaced apart relationship with said nozzle for receiving debris produced by the interaction of said high velocity stream with said rivet.    
   
   
       4 ) The apparatus of  claim 3  further provided with vacuum means interactive with said collection means to remove said debris.  
   
   
       5 ) The method of  claim 1  wherein said high velocity narrow stream has a diameter such as to produce a kerf width between 0.03 and 0.04 inch.  
   
   
       6 ) The method of  claim 5  wherein said high velocity narrow stream has a linear velocity of between mach 1 and mach 2.  
   
   
       7 ) The method of  claim 6  wherein said high velocity narrow stream is caused to complete said circular path within 1 to 15 minutes.  
   
   
       8 ) The method of  claim 5  wherein said high velocity narrow stream contains between 10 and 15 weight percent of abrasive particles.  
   
   
       9 ) The method of  claim 8  wherein said abrasive particles have a size between 16 and 500 microns.  
   
   
       10 ) The method of  claim 5  wherein said high velocity narrow stream is emergent from a nozzle positioned between 1 and 2 mm. from the first head of said rivet.  
   
   
       11 ) The apparatus of  claim 4  further provided with means for adjusting the diameter of the circular path of said nozzle.  
   
   
       12 ) The apparatus of  claim 11  further provided with a coiled conduit that supplies said abrasive-containing pressurized water to said nozzle.  
   
   
       13 ) The apparatus of  claim 3  wherein said mounting means has a base which includes anchoring means for releasibly securing said mounting means to said steelwork.  
   
   
       14 ) The apparatus of  claim 13  wherein said anchoring means comprises electromagnets.  
   
   
       15 ) The apparatus of  claim 3  wherein said mounting means includes an articulated arm having pivot hubs and interactive stabilizing brakes.  
   
   
       16 ) The apparatus of  claim 3  further comprising means for automatically stopping the flow of pressurized water to said nozzle when said nozzle has completed its circuitous cutting path.